Searchlight for the guidance or detection of aircraft



May'15, 1928.

E. A. SPERRY SEARCHLIGHT FOR THE GUIDANCE OR DETECTION OF AIRCRAFT Original Filed April 19. 1918 vwemto'c 3% %WFMR A-5PERRY. @13 me JZZLMM Patented May 15,1928.

. current STATES PATENT OFFICE.

a f rms A. .srnnmnor BROOKLYN, NEW YORK.

snnracnnicnr 1503' THE GUIDANCE or. nn'rncrron or AIRCRAFT.

Original application filed April 19, 1918, serial No. 229,485. Divided and this application. filed June 1,

1923. Serial No. 642,745.

' This invention relates to searchlights, and more specifically to means for directing the beamofa Searchlight from a distantpoint.

The Searchlight constitutes one of the essential elements in the-system of defense against enemy aircraft. In view of the high speed of flight of the latter and the ease andrapidity with which these aircraft can change course, it isimportant that the Searchlight icspond quickly l to its control and preferably that the operator may act also as observer. 1 To render this ,possible the light should be controllable fromla distance by a control to which the light will readily respond.

The Searchlight has also come into use as anocturnal beacon for guiding airplanes in times of peace, and for illuminating aviation fields. Insuch lights also, it is highly desirable to be able to direct the beam :more

or less vertically and to vary the direction of thei'beam at will, since it is found that a moving beam is muchmoreeas ly picked up pylthe aviator than a "stationary beam. 1

en the air plane approachesthe field, the i light ma also be employed to illuminate thefield y directing the beam horizontally. "One of the principal objects of the present invention is to provide a simple control meansf'fulfilling the above'requirements.

A further object is toprovide a searchand control means therefor which may readily be placed in a trench ort-renches to minimize the danger of damage either to the light or operator, due to'shell fire.

Another importantobject is to. provide an invertible searchlight capable of being kept on atarget passing directlyabove the light.

7 Further objects and advantages willappear asthe invention is hereinafter developed.

' This application isa division of my copending application for searchlights for the guidance or detection of aircraft, Serial No.

229,485,1iled April 19, 1918, patented June preferred system showing a therein.

Searchlight mounted Fig. 2 is a plan view thereof.

My invention comprises a Searchlight movable abouttwo axes, one of which is preferably vertical and another horizontal.

One form of support is shownin Fig. 1 as comprising a carriage 1 rotatably mounted on a base Zabout a vertical pivot 3. Rollwhen mounted on soft ground. ,It will be seen that by moving the searchlight about either or both of its axes the beam of the light may be directed anywhere in space.

.lrVhile the control mechanism may be lo- ..cated adjacent the light, I prefer to locate itx one side for various reasons, among whlch are the followingz When the light is employed for military purposes it is desirableto place the operating station at a substantial distance from the lamp to reduce casualties, Furthermore, it isv found that i the accuracy in. directing the-beam is enhancedas t e angle between the lines connectmg the targetand observer and the target and Searchlight is increased. A preferred" form of distant control is shown in Figs. '1, 2 and 3 and may. be constructed substantially as follows; i p y I Secured to the upright 6, either integrally as indicated in Fig. 3 or preferably dctaclr ably asindicated in Fig. 2, are a plurality of arms 10, 11. Thelast mentioned arms are preferably bifurcated at their outer extremities to form seats for the straps l2, 13 which are pivotally connected, for a purpose which will hereinafter appear, to said arms.

Preferably the connection between the straps and arms should be made detachable asindicated in Fig. 3, each pivot pin 14 being provided with a reducedportion or peripheral groove 17 into which a spring 16 is adapted to enter to hold the pin'in operative position. Obviously the pins lfl may be readily withdrawn by raising the spring .16 and exerting a pull on the head 15, De-

tachably connected, by means of bolts 18, to the outer ends of straps 12, 13, is a block 19 through which an operating member or rod 20 extends. By revolving the rod 20 about "particularly in anti-aircraft Work. thelight may be mounted ina trench T surthe The rod 20, which" is illustrated in the form of a sleeve, may also be employed for controlling the position of the searchlight in elevation; While this function may be accomplished by connecting the member20.

directly to one of the horizontal pivots 7 or 3 of the light, 1' preIer to efiect this connection through reduction gearing. The member 20 is rotatable in theblock 19, a collar 21 being mounted on said member on each side of block 19 to prevent end movement of said member. The inner end of theoperating member is connected to the shaft of pinion 22, journaled'in the upright 6- by means ofa universal joint 23. This universal joint, which is directly in line with the linev of pivots li,'is preferablydetachably connected to the sleeve 20 by means of a shank 24: adapted to enter said sleeve and to be secured thereto by means of a through bolt 25. The pinion 22 meshes with a gear 26 secured to pivot 8 of the searchlight so that by rotating theoperating member 20 the light may be rotated about its horizontal pivots and the elevation of the beam controlled.

My invention as above described'is especially adapted to be applied to militaryrllilse, us

substantially circulartrench spaced a substantial distance Preferably the oproundcd by a or runway '1" from the central trench;

erating'member should bemade adjustable in length. This may be accomplished by providing a rod 30adapted to telescope into sleeve '20 but connected thereto in such a manner as to turn therewith. One form of suitable connectionis shown inFig. 3 as comprising a longitudinal slot 31 in sleeve 20 adapted to receive aset screw 32 screwed into rod 30. Obviously the rod 30 may be pushed-into or pulledout of the sleeve 20 but on rotation of the first mentioned memher the sleeve 20 will rotate therewith. To

facilitate the control of the searchlight the rod 30 may have rotatably mounted thereon a wheel 34, which may assume'the form of an ordinary bicycle wheel, adapted to travel on the track or runway 33 to support the weight of the operating member. A manually operable member in "the form of a hand-wheel 35 is rigidly but preferably detachably secured to the free end of rod 30.

It will be seen that the searchlight 9 and all of its control is whollybelow the surface of the ground so that the chance of damage thereto'by gunfire is minimized. If "desirable a barrier'of sandbags 36 may be provided around the trench T 'foradditional protection. To control the direction of the beam in azimuth the operator in the trench T simply moves around this trench in one path the beam the operator rotates the wheel 35 in one direction orthe other.

As theoperator is stationed a substantial distance to one side of the searchlight in the direction in which the horizontal axis thereof extends it will be seen that not only is be protected against injury by shell-fire drawn bythe light, but the angle between his line of sight and that of the beam is large, resulting ,in great accuracy in directing the beam., y,

- It has heretofore been the practice to mount a Searchlight for rotation about a horizontal axis, but so far as I am aware the electrode or, carbon holders and the control box were mounted at the bottom of the drum at a position substantially midway beand control box are above the arc, damage to said elements results, due to the intense heat arising from the are. In order to render it possible to move the Searchlight, to

any position about the-horizontal axis, I

connect the control ,box &0 and the electrode holders, one of which is shown at 41, to the drum 42 of the searchlight 9, in a-position closer to one of the pivots 7 than to the other. Obviously with this arrangement the said elements 40, 41 will never be in the of'the heat rising from the arc regardless of what position the light assumes. 47 indicates a ventilatin housing "which may enclose aventilating an. i

It will be seen that I searchlight which may be readily inverted in action andzis therefore, easily kept on the target. Furthermore the distant control is simple, reliable and may be rea y assembled ortdisassembled by virtue of the detachable connections. H

In order to conduct electric currentto the light, a current conductin cable 48 may be led underground from. a distant generating plant (not shown) to the. light. Considerable slack. hould beprovided in said cable betweenwthe point where it emerges from the ground and the light in order that the latter may be rotated several times in azihave provided a ill) providedbetween the trenches T and T so;

that the opera-tor may gain access." to the light withoutexposin himself to enemy fire. Planks or boar 50 maybe placed over saidpassageways to preserve the continuity of the trackway of thewheel' '34., Any unevenness in this trackway will not interfere with the operation of the mechanism because by virtue of the pivots I4 and universal connection 23 the Wheel 34 will readily follow the profile of the trackway.

It will be obvious that my invention is equally well adapted for peace time uses in connection with aviation fields and the like.

In accordance with the provision of the patent statutes, I have herein described the principle of operation of my invention, toget-her with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various' features and elements in the combination and relations described,

some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Havin herein described my invention, what I c aim and desire to secure by Letters Patent is:

1. In combination, a searchlight, a support therefor pivoted for rotation about a substantially vertical axis, a laterally extending operating member, a plurality of arms secured to said support and extending therefrom, a strap connected at one end to each of said arms and means connected to the other end of said straps for supporting said operating member.

2. In combination, asearchlight, a support therefor pivoted for rotation about a substantially vertical axis, a laterally extending operating member, means including a universal joint whereby rotation of said member about its own axis rotates said Searchlight about a given axis and the revolution of said member rotates said search- ELMER A; SPERRY.

signature. 

